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Dec. 13, 1927. 1,652,882

M. A. WHITING AUTOMATIC CONTROL- EQUIPMENT Original Filed Nov. 17. 1922 Inventor-z Max AM/hitins;

His At to 'r ea Patented Dec. l3, 1927.

UNITED STATES 1,652,882 PATENT orr ca.

MAX A. \VHITIN G, 0F SCHENECTADY, YORK, ASSIGNOR TO, GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK. i

AUTOMATIC CONTROL EQUIPMENT.

Application filed November 17, 1922, Serial No. 601,602. Renewed Sep tember M, 119a.

invention relates to automatic control equipments for dynamo electric machines and particularly to such equipments for synchronous Converters.

One object of my invention is to provide a simple and improved control equipment of the type above referred to, in which a plurality of electromagnetically actuated devices are interconnected and operated automatically in the proper sequence under all conditions, to control the operation of a synchronous converter.

Another object of my invention is to provide in an automatic control equipment of the typereferred to, an improved arrangement for insuring that the synchronous converter has reached a predetermined speed before the field winding of the converter is supplied with direct current to pull the converter into step with a predetermined pola1';ity. v

Another object of my invention is to profvide, in an automatic control equipment of the type i'eferred'to, an improved arrangement for insuring that the converter has a predetermined polarity before it is self-excited.v Y

: Another object of my invention is to provide in an equipment of the type'referred to a new and improved arrangement for preventing the equipment from operating to effect the restarting of the converter in an improper manner.

According to my invention I provide an improved arrangement for a synchronous converter whereby the converter is started by a low voltage being impressed upon its armature winding and with its field unexcited; after the converter has reached synchronous speed, the field winding is energized from a separate source of direct current to pull the'converter into step with a predetermined polarity; after the converter has been pulled into step with this predetermined polarity,the field winding is disconnected from the separate source and is connected to the direct current brushes of the converter; and after the shunt field current has built up to a predetermined value, a high voltage is impressed upon the armature winding of the converter and the direct current brushes are connected to a direct current distribution circuit.

My invention will be better understood from the following description, taken in connection with the accompanying drawing, and its scope will be "pointed out inlth'e appended claims.

Referring to the drawing which 'shows'on'e embodiment of my invention, lis a-s nchmnous converter the collector rlngs Q'b'f which are arranged to be connected to'any suitable source of alternating current i such as .an alternating current supply circuit 3. The

converter is arranged'to supply direct cur- A rent to a direct current distribution circuit 4 one side of which is shown as ground. A transformer 5 is interposed". between thesu ply circuit 3 and the collector rings 2 ofthe synchronous converter and is provided'with suitable taps on itsSecondairy winding so that a low voltage maybe impressed upon the collector rings "when the. "converter is being started "and ahiglier-Noltage maybe impressed upon thecollector rings after the converter has been's'tarted; The contactor' 6 is arranged to establish the; connectioribetween the low volta e' tapsoffthe transformer 5 andthe co lector ring's Z and the contactor 7 is arranged'to establish the' connection between the'highvoltage' taps ofithe transformer 5 and the collector rings 2. Any other suitable switching means, however, may be used to impress'a'low voltage and'a high voltage on the collector' ring's' of the converter. I

The direct currentbrushes 8 of the convert-er are connected to the direct current distribution circuit 4 by a contactor. 9 which is arranged to connect the ungrounded brushes of the converter to the ungrounded side of the distribution circuit. It is to be understood, however, that my invention is not limited to a 'gr ounded system. The grounded brushes are shown as being connected directly to ground. Any other suit able means however, may be used for controlling the connection between the converter and the distribution circuit.

The converter may be provided with any suitable means for raising the brushes from the commutator so that they may be maintained in the raised position while the converter is being started. In the particular brush lifting mechanism diagrammatically shown in the drawing, all'but two of the brushes 8 are pivotally mounted. The pivotally mounted brushes are arranged to be raised and lowered by a motor 10, a worm and worm gear ll and a crank operated by converter under normalicondl brushes of correspon ing polarity are, how

ever, electrically connected together. \Vhen the worm and worm gear 11 are in the position shown, the pivoted brushes 8 areraised. \Nhen the worm gear has been rotated 180 degrees from the position shown, the pivoted brushes are in engagement with the commutator. Suitable limit switches 10"and' 11 are provided so that the circuit of the motor 10 is automaticallyopened when the brush raising and lowering operations are completed. As shown, the contacts 10 are closed when the brush raisin operation is' c'on1- pleted and remain close until the brush lowering operation is completed. The contacts 11 are closed when the brush lowering oper' ation is completed and remain closed until the brush raising operation is completed.

The synchronous converter is provided with a field winding 12 which is arranged to be connected to any sui able sourceofidirect current such as the generator 139i themotor generator set 14 by, means of a contfac'to'rllii. The field windingl'2 is also arrarigedtoz be he direct current of the converter by meansof the con'ta'c'tor 16. Preferably thel'field'winding 12 is arranged ,to'fhe divided: into fs'everal' sections when both of ,the c ont'actors' and; '16 I are connected across open so that" ith." converter; vbeing started, thevoltage stresses inthe field winding are reduced to ggravate In order to startafifdstopt s actroaojus i es Y a switch is rovided: whichfwhen, -ltfldsed, initiates the s tarting of the converter and, when opened, initia't' -the stopping of, the converter. ItQis to-be understood',; however, that any' other 'wel 'known' meaq$;i, winc may be either automatically orflrf 'ajnu' 11y actuated maybe used toj iriitiate the,fstarting and the stopping o flth efco nvert enlg ,jAs

shown in the drawipg', 'thefclos ng of the switch 20 connects'thecpil 2 l ofthe master relay 22' across the center emerges which may be supplied.irolnifanyisuitabl source of currentsuch as the .supplyicircii t X energizing circuit of the coil the contacts 24' on the' bru raising j nisnuwvhichare closed" only. whenthe, p ,ted brushes 8 are out of engagement j'v' 'ith 'the commutator of the 'conve rteryi.Therefore it is apparent that the: converter canoiily-be the pivoted direct current brushes of the converter are out of engage ment with the commutator. The circuit of the coil 21 also includesthe contacts 25 the relay l0 and' the contacts of the proteo tive devices which are usually provided with automatic control equipments so that the master relay 22 cannot operate to effect the starting of the synchronous converter unless these relays indicate that the apparatus is'in an operative condition. In order to simplify part of the present invention.

iriiind Sp e these protective devices have since they do not constitute a Contacts 26 are shown to indicate the drawing, been omitted,

and 27, however,

where the contacts of these protective devices may be connected. A protective device which can be built to handle a large current may be connected as indicated by the contact 26; A protective device not capable of handling as great a current may be connected as indicated by the contact 27.

After the coil 21 of the master relay 22 has been energized; the opening of the contacts -24 of the brush raising mechanism or the'openi'ng of the contacts 25 ofthe relay 40 does not deenergize the coil 2 1"because the contacts 30 of the master relay which are closed when the coil 21 is energized, completes a shunt circuit around the contacts 24 and 25. The master relay 22 is also provided with the contacts 31 which are closed when the coil 21 isenergized." The closing of the contacts 31 connects the coil 32 of the contactor"6 across the control ciredit 23' so that collector rings 2 of th'e'l con- Zverter are connected to the'jlow voltage taps foffthe'l transformer to stat tithe converter. 'llheic'ir cuit' of the'coil32 also includes the gea ctagfi e en a sfli of t ere y 34 and the contacts 36 on suitab le's'onrcef offdirectjciirrentmay be used place of generator '13,] such as a storage batter-yore rectifier. Thefrelay '40, the windgllgofd'whichis coring-i ted across the two stationary brushes, of converter, is arrhng'e d to' efiectthecohnectiomof the field l2. ofthe .cbni'cifter'to thefgenerator 13'wh e n the converter' reache's a predeter- The'rel'ay 40 isdesigned so that it operates only in response to current of a'very low frequency and' preferably 'o'nly in response to a predetermined value of direct current. As long as the speed of the converter is below sync 'ronous speed, alternating current flows through the coil 41 of the relay-l0 so that the relay remains inoperative. When, however, the converter reaches synchronous speed so that only direct current flows through the coil 41, the relay operates to open its contacts 25 and close its the coma-cm '7' which s are, closed when the contactor is open. There'- normal pOSi- Hit) contacts 42. The relay 40 is preferably of the'type known in the artas a hesitating control relay. and particularly=of the type whihis inductively damped so that it has 'a considerable" hesitating characteristic. That is'='to-'say, when the coil 41 is deenergizedfthe relay does-not open its contacts 42 until-some time later, typically one second or moreFThis feature prevents'the relay from opening its contacts '42 when the voltage acrosstlie br'u'sh'es on the commutator passes through zero in case the converter slips a pole when the field winding 12iis separately "excited or when any: other sudden change occurs in the phase position of the converter armaturF Another function of 'the relay 40 isto' pie'vent" the immediate reclosingpf the master relay '22 (after-it has opened due to anyause so thatallofthe control devices -have"-tiine "toreturnf'to their normal positions' befor-tlie master relayca'n be again i ijl igi"'zl;d to effect the restarting of the converter. lu*this miy it] is insured that the starting? sequence of operation is correct under-e11 conditions i 'Thelclosing of"thecontacts 42 connects the coil 44 of -the'contactor across the ontrol"ci'r'cuit23,"sdth'at the contactor 15 operates to dam-ea the 'field" winding 12 to the "gnei"a'tor f13.' fThe jbilclllt of the coil 44 alsoi'r icludes-the contacts 26, contacts 31 of gangster-relay 22,"conta.'cts '45 of the relay :46 and "auxiliary 'ontacts'47 .ion' the contactor are closed when the contactor is open" Therefore the contactor 15 can be clo oiilylvvlien the contactor 16 is open.

Th coil 48 ofitlie relay 46 isfconnected in tIienlocks into step with the correct polarity. It has been found that when this occurs, the separately excited .field current jiro m' the source 1 3 is so afi'ecte'd by the induced'vol tage in the converter field during the slipping that this field current does not 'attain and maintain its maximum value until the converter has thus slipped and has locked into. step at the correct polarity. Preferably the relay46 is also of the hesitating control type, inductivelydamped, and isjdsigned so that it does not open its'contacts 45 and close its contacts 49 until the .fieldcurrent supplied by the generator 13 builds up to a predetermined steady value thereby indicating that the converter is in step with the correct polarity. When the relay 46 'opensits contacts 45 and closes its contacts 49, the coil 44 of the contactor 15 is de ene'rgized so that the field winding 12 is disconnectedfrom the generator 13 and the coil 50 of the contactor 16 is connected across the control circuit 23 so that the field winding 12 is'connected across the direct current brushes 8 of the converter. The circuit of the coil 50 also includes the contacts 26, the contacts 31 of the master relay, contacts 42 of the relay 41 and the auxiliary contacts 69 on the contactor 15 which are closed when the contactor 15 is open. The closing of the auxiliary contacts 67 on the contactor 16 when the coil 50 is energized, completes a shunt circuit around the contacts 49 so'that the cont-actor 16 remains closed after the relay 46 opens its contacts 49 due to the circuit of the coil 48 being opened by the opening of the contact '15. The hesitating characteristic however of the relay 46 keeps the contacts 49 closed long enough to allow the contactor 16 to close and complete its locking circuit through contacts 67.

- The coil 51 of the relay .34 is connected in series With-the field winding 12 of the converter when the contactor 16 is closed to establish self-excitation ofv the converter. Preferably, the relay 34 is designed so that it operates only in response to a predetermined value of direct current. After the contactor 16 closes and the direct current through the field winding 12 builds up to a predetermined value, the relay 34 operates to open its contacts 33 and close itscontact's 52. The opening of the contacts 33' deenergizcs the coil 32 of the contactor 6 so that the collector rings 2 are disconnected from the low voltage taps of the transformer 5. The opening of the auxiliary contacts 37 of the contactor 6 disconnects the motor 38 from the control circuit 23 so that the motor generator set 14 shuts down. As soon as the contactor 6 opens and closes its auxiliary contact 53, the coil 54 of the contactor 7 is connected across the control circuit 23. The circuit of the coil 54 also includes the contacts 26, contacts 31 of the master relay 22, contacts 42 of the relay 40 and the contacts 52 of the relay 34. Since the circuit of the coil 54 includes the contacts 53 on the contactor 6, the contactor 7 can only be closed when the contactor 6 is open. The closing of the contactor 7 connects the collector rings 2 of the converter to the high voltage taps of the transformer 5.

It is Well known that when the alternating current connection of a synchronous machine ischanged 'from a low voltage to a high voltage source a transient disturbance is produced in the field current. It has been 'found that the field current may thus reduce to zero for a short period of time. There fore it is preferable to make the relay 34 of the hesitating type so that it will keep its contacts 52 closed during such sudden changes in the field current.

The contactor 7 is also provided with the auxiliary contacts 56 which are closed when the coil 54- is energized. -The closing of the contacts 56 connects the motor 10 of the brush raising mechanism across the control circuit 23 so that the movable brushes 8 are moved into engagement with the commutator of the converter. The circuit of the motor 10 also includes the limit switch 10' on the brush raising mechanism so that the circuit of the motor is maintained until the brushes are-in engagement with the commutator.

The circuit of the coil 54' of the contactor 9' which controls the connection between the converter and the distribution circuit 4, is arranged to be connected-across the brushes 8 of the converter after the pivoted brushes 8 are moved into engagement with the commutator. The circuit of the-coil 54 includes the contacts 55 of the direct current voltage equalizing relay 56, the contacts 57 of the master relay 22, the contacts 58 of the polarized relay 59 and the contacts 6'0 oi the'brush raising mechanism.

Thedirectcurrent voltage equalizing relay 56" is a differential relay comprising two coils- 61 and 62. .The coil 61 isrconnected across the load-circu-it- 4 and the coil 62 is connected across. the. direct current brushes 8 of the converter by means of the contacts 63 of the conta'ctor 9, which are closed when the'coil- 54 0f the cohtactor is not energized. The coils-61=a1id 62 aretso-arranged that the relay: 56-" closes its contacts-55 when the direct currentvoltage of: the converter exceeds the-voltage of the distribution circuit .4 by: a: predetermined amount; In order to maintain the coil-54v of the contactor 9 energized after! the contacto'r opensits contacts -63, the contactor is provided with. the contacts 64 whichcomple'te a shunt circuit around it-scontacts: 55-;when the. coil. 54 is energizede aflv mi 1 The contacts 57 of the master relay 22'are closed when the coil 21- is energized. A The'polarize'd rela'y 59 is provided with a coil 65 whichis connectedacross the terminals of the generator- 3.- Ilhe relay is so designed thatitcloses itscontacts; 58 only when. the direct current voltage of; the converter is a predetermined-value and in a predetermined direction.- This relay prevents the coil 54 from being. energized in case the polarity of the converter is wrong. due to the failure of some of the-other devices operating in the proper manner.

The contacts 60 of the brush raising mechanism are closed when the movable brushes are in engagement with the commutator of the converter. It is usually de si-rable to introduce a time delay between the closing of the contactor 7 and the closing of the contactor 9. With the arrangement shown the necessary time delay is obtained by means of the bnish raising mechanism which takes several seconds to complete its brush lowering operation.

It is therefore evident that the converter can be connected to the distribution circuit 4 only when the master relay 22 is energized, the voltage of the converter is correct and the movable brushes of the converter are in engagement with the commutator.

The converter may be provided with any suitable means for protecting it against short circuits and overloads on the distribution circuit. Such means are not shown in the drawing, however, because they are well known in the art and do not constitute a part of my invention.

The operation of the equipment shown in the drawing is as follows:

When the converter is shut down and all of the apparatus is in operative condition, the different control devices occupy the positions shown in the drawing. In order to start the converter, the switch 20 is closed. The closing of the switch 20 completes the circuit of the coil 21 of the master relay 22. The closing of the contacts 31 of the master relay completes the circuit oi the coil 32 of the contactor 6 so-tha't a low voltage is impressed on the collector rings 20f the converter to start the converter, and the motor 38 of the motor generator set 14 is connected across the control circuit 23. \Vhen the converter reaches synchronous speed or a speed at which the slip of the converter does not exceed a predetermined small value, the relay 40 operates to close its contacts 42. The closing of the contacts 42 completes the circuit of the coil 44 of the contactor 15 so that the field winding 12 of the converter is connected. to the generator 13 to pull the converter into stepwith the right polarity. As soon as the converter th uspulls into step and the field' c'urifent builds up to a predetermined steady" value,

the relay46' opens its contacts 45' and closes its contacts 49. The opening of the contacts 45 deenergizes the coil 44 of the co'ntactor 15 so that the field winding 12 is disconnected from the generator 13. The closing of the contacts 49 of the relay 46 completes the'circuit of the coil 50 of the contactor 16 so-that thefi eld winding 12 of the converter is connected across the direct current brushes 8 of the converter. Although the circuit of the winding 48 of the relay 46 is opened when the contactor 15 opens, the relay 46 maintains the contacts 49 closed "for a suiiicient length of time to allow the contactor 16 to close. The closing of the auxiliary contacts 67 on the contactor 16 completes a circuit for the coil 50 which is independent of the contacts 49 of the relay 46 so that the coutuctor 16 remains closed after the relay 46 opens its contacts 49. As soon as the shunt field current builds up to a predetermined value. the rclay 34 opens its contacts 33 and closes its contacts The opening of the contacts 33 (It-energizes the llll) coil 32 of the contactor ti so that the collector' rings 2are disconnectedfro'm the'low voltage taps of the transformer. As soon as the contacts 53 ofthe'contactor 6 are closed the coil54'of the contac'tor 7 isen'ergized so that the collector rings 2 of the converter are connected to the high voltage taps of the transformer. The opening of contacts37 when the coil 32 is deenergized, dis

able; brushes 8 are moved into engagement with the commutator the" converter: Whenthe brush lowering operationis com} pleted the jlimitl sw itc-h 10 opens and-the i w us 1 The' i r limit switch 10: opens the cirtuit off ng- As soon as the direct current voltage of theconverterex'ceds the voltage across the distribution circuit 4 by a certain amount, the direct'current voltage equalizing relay 56close's it sc'ontacts 5 5. If the polarity of the converter is correct, the polarized relay 59closes its contacts as soon as the direct current voltage'offthe converter exceeds'a predetermined .value. Therefore, "if the di: rect' currentvolt'ag'e of. the "c'onverter'is above a predetermined valuefand Toffthe 'right polarity when the contacts 6 O of 'thebrush raising mechanism are closed, the circuit of the coil 5410f the contactor 9 is completed. The closing oft-he main contacts 68 of the jcontactor when the coil'54 is energized, conn'ec'ts-lhe un'groun'ded brushes of the'converter to the ungrounded side of the distri-' bution circuit 4. The closing of the contacts- 64 of the contactor 9 completes a holding circuit; for the coil 54 which is independent of the contacts 55 of the relay 56 so that the coil 54' is not deenergized when the relay 56 opens its contacts, due to the circuit. of the coil 62 being opened at the'contacts 63.

The converteris now in operation and supplies current to the distribution circuit 4. The converter is shut down under normal conditions by opening the switch 20 which deenergizes the coil 21 of the master relay 22. The opening of the contacts 57 of the master relay 22 deenergizes the coil 54' of the cont-actor 9 so that the converter is disconnected from the distribution circuit 4.

The opening of the contacts 31 of the master relay 32 (leenergizes the coil 54 of the contactor 7. so that the converter'is disconnected from the high voltage taps of'the transformer. The closing of the auxiliary contacts on the contactor 7 connects the motor 10 across the control circuit 23 so that the movable brushes 8 are moved out of engagement with the commutator. The limit switch ll which' is in circuit with the motor 10 opens when 'the brush raising operation is completed so as to stop the motor.

" The opening of the'conta'cts 31 of the master relay' also deenergizesthe coil 50 of the 'contacto'r 16s0 that the field winding 12 is fldisconnect ed 'from the direct current brushes 8"of the converter and the relay 34 is restored'to'it's norinal position after a certain time. {I H a p Since the'converter 1s disconnected from;

alternating currentfsou'rce and the field-cirouit is open the direct-current voltage'of the converter' decreases below the drop out point of {the relay "'40 so 'that it is restored to 'its normal position after af certain" time. The converter is nowcompletel'y shutdown, awaitin thef'clos'ing of the switch 20.

- The s uttingidow'n'of itheconverter mayalso' be efiected by any'bne ofi th e protective devices opening its respective contacts 26"or'27 in the circuitof the coil' 21 of the master relay 22. The shutting down'operation will be the same as above described. In case howevert'the abnormal condition which causes the converter to shut down is of a momentary 'character the shutting down operation' is the'sameas above'described except that as soon "as the raising operation of the brushes is. completed-and the voltage relay 4O closes its 'contacts 25; the masterrelay 22 is again energized and 'the'heretofore de scribed starting operation is repeated. "The time required; forthe' brushgraising mechanism to complete'itsbr'ush raising operation, afterjthe -co nta'ctor 7 opens, "is long enough 'so' that allof theothercontrol devices havereturned to their normal positionswhenthe contacts 60'are closed. -In automatic contrdhequipments for synchronous converters which are not' provided with a brush raising mechanism; the relay 40 may be so designed that it does not drop out until after all of the other devices have had time to return to their normal positions. Thereby the proper starting sequence of operation is insured.

' While I hav e'shown and described only one embodiment of my invention. I do not desire to be limited thereto, but seek to cover in the appended claims all those modifications that fall 'Within the true spirit and scope of my invention.

hat I'claim as new and desire to secure by Letters Patent of the United States, is: 1. In combinatiom-an alternating current source, a synchronous converter, switching means whereby'said"'conyerter may be connected to source, a source of direct current, means'whe'reby' the field winding of said converter may be connected to said source of direct current, and means arranged to be'operated by the current supplied to the field winding by said source .of direct current to etfectthe connection of the field winding to the direct. current brushes of said converter.

2. In combination, an alternating current source, a. synchronous converter, switching means whereby said converter may be connected to said source, a source of direct current, means connected and arranged so that it operates in accordance with thespeed of said converter to effect the connection of the field winding of the converter to said source of direct current, and means arranged to be operated by the current sup:

conv er tr t au i-s r e s i idr rr ct 91 rent builds. upi-to a1prodeterlmn d,v value 150. fec e n t Jiet-[tbe lfi dn wmdving to ,tfl ei direct;currentbrushes of. the con? l t -.1 2? c 9 r-fl r. LE1- In c mb n o n: eieatii fi isnt eam yne myqu 1 e rertqrr swi hing meansa he y resta m nt-be 99.? me ed to: sa sisaume a torment d rectrur: nt, means, pera ive miresn a sate t vo a e acr ss-lbs dir vnq rm tvtermmal aid qa rte t st-1 th aeeqtiae of; th lfieldind n l t I seamen miter, to aid rei tdireqtzsweat-and;were r? ang dato: be, operated yby fl qflqurrent supr plied to. sa d, fie :Wia a new sa d s ers d r t-cur e rtqa-efie t-h QPQM QUW qmn -fi drwint1 gteth act ur rt terminals of said converter. 9,. ,t

1' ,5" In: combination, I an, alternating current s u ce, y chrea us emsrt c srT c in eans he by a sai lf m nter may e Et nn cted t dso r ena .sd r aqi-dir ct cm: rent, a relay connected: across the direct cur,- rent brushes of said converter-and, arranged to be operatedionly in, respons e to a predetermined value, of unidirectional current for etfectingtheconnection of the f eld winding pf-said converter to said source of direct current, and means arranged to beoperated by the currentsupplied to said field winding from said source of direct currentgior efiecting the connection of the fieldzwinding to the direct-current brushes of said converter.

6. In combination, an alternating current source, a synchronous converter, switching means whereby saidconverter may be Icon nected to said source, a source of direct current, a hesitating control relay connected across the direct current brushes of said converter 'for effecting the connection of the field windingof said converter to said source of direct current, and means arranged to be operated when the current supplied to the field winding of the converter from said source of direct current builds up to a vpredetermined value for ell'ecting the connection of the field winding of said converter (tojhe direct current brushes of the con e er 7. In combination, an alternating current source, .a synchronous converter, switching meansarranged to connect said converter to said source sothat a low voltage may be impressed .luponsaid converter, switching means arranged to connectsaid converter tosaid sourceso that a high voltage may be impressed upon said converter, a' source of direct current, meansoperative to effect the Qperationiot said, first mentioned switching means, whereby the hold winding of saidlfconvert'er ,may ,be, connected to said source ot direct, current,f mea'ns operative in responsetqthe current supplied to said field winai l l -Oh Said 26? Di direct cur to fefiegtthe fconnection of said field winding to, thefdi qctfcurrentbrushes of said conrerte' sl nndmea w er by: he pera on. of saidse jqndg enti iiegswitching means may be'i'efiectc gfift the field i'n'dingjis con: nectedto the direct current brushes ofthe cqnxe tln I; j,

8.5 combination,- an alternating current source fi synchronous converter, switching to' co'nnect' said lcon verter to m. spar so that elm? flelta'g ..i$- i .res ed lpflilt ldmiqlwg i fi i .gs s h glmea range, to 'confiect "said lconvcrter to. said source so' that 'a ;high' vo l t age' is impressed uma mcpm t a,' source of direct current jn 3,55 5 at e. to effect the operation ii. sa l i. lst-l, li iened 's 'itehi s m ns a he ebmh fi h indin f i1 convrterinay'b'e' connected to's'aid"so.ur'ce of ixs tgurreat mews e rat v n. resiwn e to h e at: Su p ed to s d. fie d windin fironi 'soiurcgi f ,direct' current to effect the connection, at said field winding to the di' sj tc rrentbr h sfo sa d 'bnve it arid niea-ns operative in rcspfonscg to the current suppliedto said field winding froin the direct current brushes to. effect the operation of'saidfsecontl mentioned switching means.

' ,9. In combination, an alternating current source,,a synchronous converter, switching means arranged to connect said converter to said-source so that a low voltage is impres ed upon said converter, switching means an ranged to connect said converter to said source so that a high voltage is impressed upon said converter, a source of direct curits rent, means operative to efiect the operation of said first mentioned means, means conneeted,and}arranged so that its'operation'de pends upon theislin off converter to effect thej connection of the field winding of said'conver'ter to said source 'of direct curr'ent,"nieansjoperative in response to thec'ur rent supplied to "said field winding from said sourceof dlrect currentto effect the connecl f said converter to d rect chrrent brushes of said; converter, andr'neans operativeinresponse to the cur rent slippliedto said jgi'eia windinj from the dire reatheeswa ez r p' a of sai ,sgqopd"mqntign e wi chiagj ga s. 41 19;" Ia some 21 aal m r e e ew wee new; wes hin 1 s rra ge. d the a te n i ,Qurr'ent term nals of sa d converter to -said source so; "that a) voltage is "impressed ,npo

i d; t rmina s, 1 fsvj t in' ea s l rr'anged ,t 'co 1 inect gtli alternating current terminal "of converter to 'said source @Qjhat a ltage is impressed upon sa'idje i m lsga sour'ce of direct current, means 'o era ve' to' effect the operation of v 1 entlon'e'dswitching' means, means nals effect) fee- @1611 of said second {mentioned sw tching means.

I 211:. In an alternating current source, a synchihnoiis converter,'s\vitcl1 'mean'sarranged'to connect said converter tofsaid sourcefso' thata low voltageniay' begiinpressed upon said converter, switching ineans'larianged to connect said iconverterd o "saidf source "so that high 'voltage'inay be"impressed upon said converter, a so urce of direct,(zurrent, means opijerative' to efi' ct the operation of said first 'rnentioned means, means cdnnect- Led and arran ed so that its operation de- -ggiids upon .th s'lip of said converter'to effect connectionof the field winding of 'sfaid'con verter'to said'source of direct current, means whereby the field Winding of s aid iconverter may be connected to the direct *c urrent brushesofsa'i'd converter after the fieldvvindihg hashen connected'to said diirectljcurif'erit source and "means operative in gas s-i1" to the'current "supplied to said=fie1d the direct current brushes to eiie'c tfthe o peration"of said second" men- ;it n' id awin means f 121' In combination; an alternating current a' Synchronous converter, "switching means-whereby saidc'onv'erter may beconfrom said direct current terminected to said source,"a sourceof direct'current, means whereby the field winding of said converter 'may he *connectedto-"said source of direct Y current; and "ai relay connec t ed in series with'the c iicuit'cornprising said source 'of 'direct current and the field Winding bf said converter and arranged so' thati t op erate stb effect the connection ofthe field'windi ngofsaid converter to the direct ciirrent brushes-ofsaid 'c' onverter when the, current in fsaid *circuit; builds Z to a predetermined"steadyvalueif syafl 13f combination,- an alternating current source; synchronous converter; switehing meaaswhemb said converter may be com nectefd' to 'said= source; a source o direct-tcur+ area's; Ea "hesitatingeontrol 'relay connected aerossthe direct Current'hrhshs oi Said goon;- ve'rter'and arrangedto effect the connection of the field Winding pfisaid converters-to "said sonrcecf' direc't curient,'i and m relay connected in series vvith the ei r'cuit'icompriszing said source of 'directieurrent and'the field winding of saidconverter and arrafiged to eflfct" the connecti'on of the' field. winding of saidconverte'r to the dii ect 'eurrent :brushe's of said converter 'vvhen the current inrasaid circuit builds up to 'a" predetermined-steady "illnel "'3 ."i. "."'7'-"?*;"'Y f. "I 14; In combination; an alternating current source; a synchronous converter; switching fmeansf'arrangedto connectisaidr converter ito said 'sourceso that- 'a'low hroltagermay impressed upon said converter, switching means arranged to connectsaidrconvei ter .to said source so that 1 a :high' voltagemay be impressed upon said 'converter; 3, source of direct current; afirelay i connected across ithe direct current brushes ofsaid oon've'rteri and arranged to e'fi'eet the connection of the.- field iwinding of said co'nvert'erto said souree'of direct current,- Wlien the voltage across the direct "current brushes attains "a :unidire- 'tional state, a relay connected in series-with the circuit comprising said source of direct current and the field winding ofsaidco'nverter and arranged to effect the connection ofthefield winding of said converter to the direct current brushes of said converter when the current in said circuit huilds up to a predetermined' steadyvalue, anda relay connected in series with-the circuit comprisingthe field Winding of said converter and 'the direct 'current brushes of said-converter fand' arranged-ti) effect the operation of said I second mentioned switching means. when the shunt-field current builds up=to zit-predetermined'steadyvalue. a1"

' 15; 'InT comhinatioh; an alternating .Vcurrent source; a -'synehr'im'ous convqter, switching means arranged toieo'nnec't said converter 'to said source'- so" that* -a' low'voltage may be impressed upon sai 'd converter; switching means arranged toconnect said converter to said sourcg'so that a 'highdvolta'gemay :be

impressed upon said converter, a source of direct current, a hesitating control relay connected across the direct current brushes of said converter and arranged to effect the connection of the field winding of said converter to said source of direct current when the "oltage across the direct current brushes attains a unidirectional state, a hesitating control relay connected in series with the circuit comprising said source of direct current and the field winding of said converter and arranged to effect the connection of the field winding of said converter to the direct current brushes of said converter when the current in said circuit builds up to a predetermined steady value, and a hesitating control relay connected in series with the circuit comprising the field winding of said converter and the direct current brushes of said converter and arranged to effect the operation of said second mentioned switching means-when the shunt field current builds up to a predetermined steady value.

16. In combination, a source of alternating current,,a synchronous converter, switching means arranged to connect said converter to said source so that a low voltage may be impressedcon said converter, a second SWltCll ing means arranged to connect said converter to said source sothata high-voltage may "be impressed on said converter, a sour of direct cur-rent,v an .electromagnet arranged .when energized to effect the operation of said first mentioned switching means, an energizing circuit-for said electromagnet, an electromagnetically operated means arranged to connect said source of direct current to the field winding of said converter, a circuit for said electromagnetically opera ed, means, means controlled by the, voltageaacross the direct current .brushesof said; CQ B'QI Q Q controlling contacts in the circuits of said electromagnet and said electromagnetically operated means, and means, whereby the field winding of said converter is connecmd to the direct current brushes ofsaid,c01 1ver,ter and the operation of said sec'ondswitching means is effected after the field winding of said converter is connected to said source of direct current. Y

17. In combination, .a source oi alterna ting current, asynchronous converter, switching means arranged to connect said converter to said source so that Ea low voltage may be impressed on said converter, a second switching means arranged to connect said converter to said source so that a high voltage may be impressed on Said'conyerter, a source of direct current, anelectromagnet arranged when energized toefi'ect the operation of said firstmentioned switching means, an energizing circuit for said electromagnet, an electromagnetically operated means arranged to connect said source of direct current to the field Windingof said converter, a

circuit for said electromagnetically operat d I means, a hesitating control relay connected across the direct current brushes of said converter for controlling contacts in the circuits of said electromagnet and said electromagnetically operated means, contacts in the energizing circuit of said electromagnet connected in parallel with the contacts controlled by said hesitating control relay and arranged to be closed when said electromagnet is energized, and means whereby the field winding of said converter is connected to the direct. current brushes of said converter and the operation of said second switching means is efiected after the field winding is con; nected to saidsource of direct current.

18. In combination, a source of alternating-current, a synchronous converter, switching means arranged to connect said converter to said source so that a low voltage may be impressed on said converter, a second switching means arranged to connect said converter to said source so that a high voltage may be impressed on said converter, a source of direct current, an electromagnet. fiflianged when energized to effect 'tliefope'ration of said first mentioned switching means, an energizing circuit for .said' eleetromagnet, means ewherebycertain ofthe. direct curlfent brushes of the'convertermay beraised and lowered, contacts in said energizing circuit controlled. by said, last. mentioned means whereby said energizing circuit completed o y wh the brushe'stcontre ledby said last mentioned :means are raised,f means wherebythe field ivindingoi Said converter is connectedgto said source of direct current when the speed of the converter reaches a predetermined value, means vwhereby the field nding 0i a di me ter i conne e to th direct currenthruShes of said converter and he pera iom oi said second switching means .i e ec d miter h fieldaviudi g is c n ect- .ed t isaid so m Qtdir ct urr nt andmee ont e ed by. s d secondsv' tc' ng mean tor; efificting the operation of said brush ai ing a da ower ng an 4 1 eombr'nat i se rceoi ltern t rrent, syn h on u .cenve enfswi i g means whereby saidconverter maybe connected to .said. sour e s t a loiw v a y be mpressed up n: d o erte swi h ng me n h r by s i o r y be eonne d o sa d source so that high voltage may, be, impressed upon. con- 'verter, a d rect current generator, ,driving means for. said. generator, means adapted n p ted. o efie the. operati n f said first mentioned switching means and the operation of said driving means, means connected. and arranged so that its operation depends upon the speed of said converter to effect the connection of the field winding of said converter to said generator, means whereby the field winding of said converter field current foreffecting the operation of said second mentioned switching means.

i 245. In combination, a source ofalternating 1 current, a synchronous converter, automatic switching means adapted to control the connection between said'source and Said converter and the excitation of said converter,

is self-excited and :said' secondswitching means is operated a-fterthe polarity of saidconverter is correct, and means controlled by said first mentionedswitching-means for rendering said drivingmeans inoperative. 20. In combination,'a source'of alternating current, a synchronous converter, switchingme'ans whereby said' convertermaybe f said means comprising a control relay which connected to said source so-that/ a low volt-" is arranged to'be energized at a predeteragemay be impressed-upon'said converter, mined point in the sequence of operation-of switching means whereby-said converter may i s t g meilns'to efiect f r her p beconnected to said "source so thata'high ation of said'switching means, amaster relay voltage may be impressed upon said'con arranged when energ zed to effect the op er* verter, means responsive'to' thevoltage across atlon of' said" switching means to =c0nnect the direct currentterminals of said converter; said converter to said source and to control for applying the excitation of' said converter,- d m responsive t th -fi ld urr n of 1 predetermined polarity is obtained'acro'ss the time;

"saidconverter forcfiecting the-opemticn of? i t r r s f he nverter' nd said scpnd"mentionedxswitchingg m sge whendeenergized-to effect the disconnection 21'.- In*combination,a source ofalternatof sald-conyerter-from said source and the ing'curr'ent, a synchronous converter, switchdeenergizat on 'oi" 1i control y, and i r an h by aiduc s f 'ima 156 means controlled by said control relay for hect d' w g ;id 1 53 tha ,"1d v 1t controlling' said master -relay so that it can gu yimpressed a an b s r z besreenergized onlygaftersaid control relay switching ineaiis whifeby' said iioifverti"may be*connected"to"sa;id-; thati' a higlij voltage may be imc'r seaupc 1i saidco1c a, v, r :VertQr hes-ifatiflgrcfiffbp (bifii t dii ll'lgi current, afsynchronous conyerter, auto; across, the direct cuireiit terfiiina s df s'a'id aP g' l f p g. P v g 5 z p gg figs g Sai-v i; rahty of devicesancludinga'relay responsive t g g mgga n 5gbtoithed1recticurrent voltage'of theconverter" sponsive tofthei'field" adaptedio' control the COIIIIQCl/IOII between vert'en for efiectingfthe op "Said -source and said converter'and to consecond iatnnbnaa swiahifiwnansw texcltatwn'of a e etmasfer aa' ratoiabiaatita ssurc ar aesaaaiiig e r jw rgi d effect he a g g fi w i g operation of said automatic sw tching'means means-"whereb'y'said'cbnverter maj mecbfia fi n saldconvertel to sa1d "50111396 n 'nectedto said source so that, a low.v61tage i Q' s se s r g a maylbe nnprsg'ed ugosi-saidijtaavrper, P I F dPQ Y q b 'd pe c os switching ineaiiswhereby-sa1d bo'iit eirteii -inay he "dlrect Q b s the orilverter' be connficteitto saiigqqme so that a high andavhenideenergmed to' efiect the discon' vohgifimyr g r sjed upon said nection of SZIdLCOIiVBI'tGI from said source" verter, means where y the field winding of and the l of l Voltage y, said converter may be connected across the an energlzmg m sa1d master y, direct current brushes of said converter, a and contacts in sa1d circuit controlled by said a hesitating control relay connected in series Voltage relay that sa1d master relay can with the circuit comprising the field winding 9 Yeenerglzed ly after sa1d Voltage relay of said converter and the direct current h been deenel'glzed predetermined brushes of said converter for effecting the tlmeoperation of said second mentioned switch- In comblnatlon: 3 Source Of alternati means lng current, a synchronous converter having 23 I bi ti a source f lt ti a field windlng; automatic switching means current, a synchronous converter, switching comprlsmg a Pl y of devices including nqeans vhe eby said converter may be con- ZL relay IQSPOIISIVG t0 the voltage across the nected to said source so that a low voltage direct current brushes of the converter may be impressed upon said converter, adapted to control the connection between switching means whereby said converter may said source and said converter and to control be connected to said source so that a high the excitation of said field winding, a masvoltage may be impressed upon said conter relay arranged when energized to effect verter, means whereby the field winding of the operation of said automatic switching said converter may be connected to the direct means to connect said converter to said current brushes of said converter whereby source and to control the excitation of said said converter is self-excited, and means refield winding so that a predetermined posponsive to a predetermined value of shunt larity is obtained across the direct current the excitation of said converter so thata has been 'ideenrgiz ed for a predetermined 25. .:I1r combination, a source of alternat- IEO ane, witcl ingkmeans; for controlling ithe connection ofgsaid; converter. to said source,-v saidjneans ,comprising brush raising'mechanism,. a master relayij vhich \Vll8Il energized eil'eqtsg, the )pe 1-'ationi=iQf sa-id automatic wit hing m nus; tenement; i i-convoerceri-w sa id .,sq1 1 rce, and when ,deenergized effects the disconnection; of said converter; from, said source, an energizing circuit-forsaid, master a fl (3111B; controlled,by sard brusli .r'a'ismg ,me haim ir rebys idmaster' relay can :be: ener:

gi zed to effect the startingof .said i converter: DlXuWhemthe converter lirushesare raised; 28. In combination, a source of alternating,

curreng a synchronous ,CD iVQEtr, automatic switching means forz controlling the. starting: of said converter, ,said -,meansijcompr1sing brush raising'niechanism, a.-,eontrolrelay, ar-:.

ranged when energizfidto effect the operation of automatic switching: means" to start:-

said-eonverten an energizing circuit for said control relay," contacts n $8.l( lenergizing ctr-- cuit controlled by said-brush raising :mechaigized ,to effect. thestarting of said converter and means responsive to the .enrgijzation; of i said contr'olrelay for completing a circuit for said control relay independently of said contacts. I

nd contacts, in. said. energizing eir-' 29.3111, combination, a ,synchronous converter, a soi'uice of alternating eurren t, means for connecting said converter to said source conver ter,-,a motor generator set for supplying. eurrent,to t he field winding of said eonverter,,- and ;means controlled by said first mentioned switching means for controlling starting and stopping. of said motor generator set.

30, ,In. combination, a synchronous converter, asource of alternating current, means fogppnnecting said;.cQnV !fter to said source sq as; to; ,jnipress; a, relatively, low starting voltage on said, converter; means for connecting said,eon'\ferter tovsa id source so as to impress normal qperatingvoltage'on said convegter,,a n1ot0,1' ,driyen exciter, a circuit for the II IlQiZ 0 X Of S ad,-mQt0r driven exciter con- QlLe 'h-by a eid fix tme i n d. switching m ans-set e? a site t sc mp when k l l l wii' wt fi means is leed a d ea s imuit spp when said st i ieet e st w tch ng; ei op izeeiaese ee t means v r. connecting said new fie d wi ings said nv n. imsensisen e lee... y.v e et t smset ei .e i i i s c nefihe connect on. 0 the field winding from the. exciterand tl ie'connection ofthe field winding to the direct? current brushes goithe converter ili n ism whereby. said control rela'y can be enerassassins subse u opnina l i rst mentioned switchingmeans and the osing the secondrmentioned switchonly when the converter; brushes are raised,.-'

apsa sm 1 liminess whereof, II have hereunto set my; 'thisiGth day of November,;1922.

swarms. 

